Pathologic findings on ruminant enteric clostridial diseases reveal specificities and differences among iota and iota-like toxins

The iota toxin (ITX) is a binary enterotoxin produced as a protoxin by Clostridium perfringens (C. perfringens) type E that is activated by proteolytic enzymes in the small intestine of infected animals. By depolymerization of the actin filaments, ITX causes cytoskeleton disorganization of cells promoting the increase of the cell permeability. Here, we conducted this review aiming to advance the understanding of enteric clostridial diseases caused by C. perfringens toxins and the specificity of ITX in the intestinal mucosa lesions. ITX consists of an enzymatic component (Ia) and a binding component (Ib). We screened the recently published histological findings of the ITX effects and its relationship with intestinal enteric diseases. Histologically, hemorrhagic necrosis and multifocal hemorrhage have been observed in the jejunum-ileum mucosa, the small intestine, and the abomasum. Although the diagnosis is still based on the presence of toxins in the intestinal contents and the clinical and/or histological history, it is important to develop novel enterotoxemic indicators capable of establishing precise methods for differentiate the actions of ITX and other toxins involved in the infectious process of C. perfringens type E.